The formation of composite shipping cartons by bonding low density plastic foam to the inner surfaces of the fiber board panels forming the carton has been known for some time. One such composite container is disclosed in U.S. Pat. No. 3,344,973. However, because of the excellent insulating properties of both the foam and the fiber board material, the lamination of such cartons does not lend itself to heat sealing techniques. As a consequence, special bonding agents and adhesives must be utilized to achieve such lamination. In addition, the laminating apparatus used to make such cartons must be adapted to handle both the fiber board and the foam material simultaneously, causing processing complexities because of the cumbersome and rigid materials being bonded together. Furthermore, the manufacturer of such composite cartons will have to maintain relatively large inventories of both the foam and fiber board, which require relatively large storage space. In addition, shipment costs of the completed cartons are relatively high because of the bulky and rigid nature of the composite carton consisting of two layers bonded together.
The principal object of this invention is to provide an improved shock-resistant container or liner which may be readily set up in box form.
Another object of this invention is to provide an economical method of fabricating shock-resistant liners.
A further object of this invention is to provide apparatus for fabricating shock-resistant liners of synthetic plastic foam from unitary sheets of foam.
The above and other objects and advantages of this invention will be more readily apparent from the following description and with reference to the accompanying drawings, in which:
FIG. 1 is a plan view of a liner blank made in accordance with this invention;
FIG. 2 is a perspective view showing the liner set up for insertion into a packing carton;
FIGS. 3-7 are partial perspective views showing alternative hinge constructions, on an enlarged scale, of liners embodying this invention;
FIG. 8 is a plan view of a machine embodying this invention;
FIG. 9 is an elevational view of the machine shown in FIG. 8;
FIG. 10 is an elevational view showing a portion of the machine;
FIG. 11 is a side elevational view of a component of the machine; and
FIG. 12 is an end elevational view of the component shown in FIG. 11.